Sensitivity to single neuron perturbations in developmentally regulated networks

It has recently been discovered that single neuron stimulation can impactnetwork dynamics in immature and adult neuronal circuits. Here we report anovel mechanism which can explain in developing neuronal circuits, typicallycomposed of only excitatory cells, the peculiar role played by a few specificneurons in promoting/arresting the population activity. For this purpose, weconsider a standard neuronal network model, with short-term synapticplasticity,whose population activity is characterized by bursting behavior.The addition of developmentally regulated constraints on single neuron excitability andconnectivity leads to the emergence of functional hub neurons, whoseperturbation (through stimulation or deletion) is critical for the networkactivity. Functional hubs form a clique, where a precise sequential activationof the neurons is essential to ignite collective events without any need for aspecific topological architecture.